Enner Valencia scored twice as Ecuador spoiled the party by beating hosts Qatar 2-0 in the first game of the World Cup.

Valencia had an early goal contentiously ruled out for offside at Al Bayt Stadium on Sunday but Qatar were unable to heed the warning.

The clinical captain become Ecuador's leading World Cup goalscorer with a tally of four by opening the scoring with a penalty and struck again with a bullet first-half header.

Qatar looked out of their depth in their first ever World Cup match, failing to register a shot on target as Ecuador made an encouraging start in Group A.

Valencia looked to have put La Tri in front with a header in the third minute after goalkeeper Saad Al Sheeb flapped at a free-kick, but eyebrows were raised when Michael Estrada was deemed to be marginally offside following a VAR check.

The striker was not to be denied 13 minutes later, coolly sending Al Sheeb the wrong way from the spot after the shaky keeper brought him down.

Valencia capitalised on Qatar's defensive frailties again just after the half-hour mark, rising unmarked to meet Angelo Preciado's whipped cross from the right with a brilliant header that found the bottom-left corner.

Qatar had not posed a threat but Almoez Ali somehow nodded wide from close range right on the stroke of half-time.

Valencia required treatment for a knee injury late in the first half but was able to continue and Ecuador continued to dominate after the break, Al Sheeb palming away Romario Ibarra's strike.

Qatar were devoid of ideas and Mohammed Muntari fired over when a rare chance came late on as Ecuador eased to victory, although there was concern when Valencia was withdrawn with 15 minutes to go seemingly still being troubled by that knee problem.

What does it mean? No home comforts for Qatar

Qatar came into their first World Cup as huge outsiders and the champions of Asia showed why as they became the first host nation to lose the opening game of a World Cup.

Ecuador knocked the ball around with much more confidence and Valencia's composure in front of goal proved to be the difference.

Gustavo Alfaro's side have now kept seven consecutive clean sheets, with bigger tests to come against Netherlands and Senegal.

Clinical Valencia makes history

Valencia started the game as his country's joint-leading World Cup goalscorer along with Agustin Delgado on three and wasted no time in setting a new record.

Having found the back of the net three times in Brazil eight years ago, he has now scored each of Ecuador's past five World Cup goals. Eusebio (Portugal 1966), Paolo Rossi (Italy 1982) and Oleg Salenko (Russia 1994) hold the record of scoring six in a row.

Al Sheeb fails to rise to the occasion

Qatar started poorly and never recovered, with keeper Al Sheeb fortunate to be given a let-off by the VAR after making a mess of trying to deal with a set-piece before Valencia nodded in.

He then brought Valencia down after the Ecuador skipper rounded him and looked all at sea.

Key Opta Facts:

— Qatar have become the first host nation to lose their opening game at that edition of the World Cup (W16 D6 before today).

— Ecuador have kept a clean sheet in each of their last seven matches in all competitions (W3 D4), with Argentina's Julian Alvarez the last player to score against them back in March. 

— Ecuador  scored twice in the first half of a World Cup match for the first time. This is the second time in their four appearances at the World Cup they have won their opening match, with the other also being 2-0 (against Poland in 2006).

— There were just 11 shots in this game (5 for Qatar, 6 for Ecuador) — no World Cup match on record (since 1966) has seen fewer attempts.

What's next?

Qatar head to Doha to take on Senegal at Al Thumama Stadium on Friday, when Ecuador face Netherlands at Khalifa International Stadium in Ar-Rayyan.